Unreal engine 4 renders black on OS X Yosemite

I have a project that I’m working on, mainly on Windows, but as I have to go to Bootcamp to run windows on my MBP, it’s a pain in the butt. So I’ve set everything up on OS X, but when opening the project, the viewport is just black no matter what I do. Tried building and playing, same thing. Is this due to some bad config somewhere??

Thanks